Prostaglandins play a major role in the inflammation process, and the inhibition of prostaglandin production, especially production of PGG.sub.2, PGH.sub.2 and PGE.sub.2, has been a common target of antiinflammatory drug discovery. However, common non-steroidal antiinflammatory drugs (NSAIDs) that are active in reducing the prostaglandin-induced pain and swelling associated with the inflammation process are also active in affecting other prostaglandin-regulated processes not associated with the inflammation process. Thus, use of high doses of most common NSAIDs can produce severe side effects, including life threatening ulcers, that limit their therapeutic potential. An alternative to NSAIDs is the use of corticosteroids, which have even more drastic side effects, especially when long term therapy is involved.
Previous NSAIDs have been found to prevent the production of prostaglandins by inhibiting enzymes in the human arachidonic acid/prostaglandin pathway including the enzyme cyclooxygenase (COX). The recent discovery of an inducible enzyme associated with inflammation (named "cyclooxygenase-2 (COX-2)" or "prostaglandin G/H synthase II") provides a viable target of inhibition which more effectively reduces inflammation and produces fewer and less drastic side effects.
In another portion of the arachidonic acid pathway, physiologically active leukotrienes, such as leukotriene B.sub.4 (LTB.sub.4), leukotriene C.sub.4 (LTC.sub.4) and leukotriene D.sub.4 (LTD.sub.4) and other metabolites, are produced by the 5-lipoxygenase-mediated (5-LO) oxidation of arachidonic acid. These leukotrienes have been implicated in various inflammation-related disorders and allergic diseases, and thus compounds which inhibit leukotriene A.sub.4 conversion to leukotriene B.sub.4, such as compounds which inhibit leukotriene A.sub.4 hydrolase are useful in the treatment of disease states in which leukotrienes play an important role.
It is believed that selective inhibitors of cyclooxygenase-2 and of leukotriene A.sub.4 hydrolase, which affect the two enzymes at low concentrations, will decrease the incidence and severity more completely. These compositions also will beneficially affect the damage caused by the various inflammatory diseases and inflammation-related disorders mediated by cyclooxygenase-2 and leukotriene A.sub.4 hydrolase. These compositions also will not have the level of gastrointestinal side effects commonly associated with traditional NSAIDs.
Compounds which selectively inhibit cyclooxygenase-2 have been described in U.S. Pat. Nos. 5,380,738, 5,344,991, 5,393,790, 5,466,823, 5,434,178, 5,474,995, 5,510,368 and WO documents WO96/06840, WO96/03388, WO96/03387, WO95/15316, WO94/15932, WO94/27980, WO95/00501, WO94/13635, WO94/20480, and WO94/26731.
Compounds which inhibit 5-lipoxygenase have been described. U.S. Pat. No. 5,234,950 describes tetrahydrofuran derivatives. U.S. Pat. No. 5,098,932 describes cyclic ether derivatives. U.S. Pat. No. 5,354,865 describes tetrahydropyrans. Acetylene derivatives have been described as having 5-LO activity in WO92/01682.
Compounds which inhibit cyclooxygenase and 5-lipoxygenase have been described. U.S. Pat. No. 5,298,521 describes pyrazole thiocarbamates. U.S. Pat. No. 5,242,940 describes pyrazoles as inhibiting both enzymes. U.S. Pat. No. 5,356,898 describes ditertbutylpyrimidines. However, these previous mixed inhibitors do not selectively inhibit cyclooxygenase-2 and therefore still cause the gastrointestinal side effects which substantially reduce their usage and effectiveness.
Combined therapies of NSAIDs and other reagents are known in the art. Brooks and Karl describe the treatment of hay fever with combined antihistamines and a cyclooxygenase-inhibiting drug (flurbiprofen) (J. Allergy Clin. Immunol., 81, 110 (1988)). J. Basmajian (Spine, 14, 438 (1989)) describes the combination of the analgesic diflunisal and an antispasm agent in the treatment of back pain. V. Fossaluzza and S. DeVita describe the combined therapy of ibuprofen and an antispasm agent to reduce morning stiffness associated with primary fibromyaglia syndrome (Int. J. Clin. Pharm. Res., XII, 99 (1992)). R. Greenwald et al. (J. Rheumatol., 19, 927 (1992)) report the combination of tetracycline and the NSAID flurbiprofen ameliorates the tissue damage associated with rheumatoid arthritis.
Combination analgesics have been reported (W. Beaver, Am. J. Med., 77, 38 (1984)) although such combinations do not substantially reduce adverse effects.
The combination of NSAIDs and steroids have been described. A combination of indomethacin, steroid and lipopolysaccharide has been reported for the treatment of spinal injury (L. Guth et al., Proc. Natl. Acad. Sci. USA, 91, 12308 (1994)). G. Hughes et al. describe combinations of corticosteroids with NSAIDs for the treatment of sunburn (Dermatology, 184, 54 (1992)). C. Stewart et al. (Clin. Pharmacol. Ther., 47, 540 (1990)) describe the combination of naproxen and methotrexate as safe, although concurrent administrations of methotrexate with other NSAIDs have been reported to be toxic and sometimes fatal. A combination of a dual 5-lipoxygenase/cyclooxygenase inhibitor with a glucocorticoid is described for the treatment of skin disorders (K. Tramposch, Inflammation, 17, 531 (1993)). Combinations of NSAIDs and steroids should be used in the treatment of scleritis only if patients are not responsive to any other treatment (S. Lightman and P. Watson, Am. J. Ophthalmol., 108, 95 (1989)).
Combinations of cyclooxygenase inhibitors, lipoxygenase inhibitors, collagenase inhibitors and cytotoxic agents have been used in the treatment of non-small-cell lung cancers (B. Teicher et al., Cancer. Chemother. Pharmacol., 33, 515 (1994)).
Combinations of naproxen with other NSAIDs have been described in the treatment of arthritis. R. Willikens and E. Segre (Arthritis Rheum., 19, 677 (1976)) describe the combination of aspirin and naproxen as being more effective than aspirin alone for the treatment of rheumatoid arthritis. Naproxen and acetaminophen together were described for treating the pain associated with arthritis (P. Seideman et al., Acta Orthop. Scand., 64, 285 (1993)). However, combinations of naproxen with indomethacin or ibuprofen offer no advantage in the treatment of arthritis (M. Seifert and C. Engler, Curr. Med. Res. Opin., 7, 38 (1980)). European patent document EP485,111, published May 13, 1992, describes the synergistic combination of lipoxygenase inhibitors and NSAID's for the treatment of inflammatory disease.
There have been no reported combinations of a cyclooxygenase-2 selective inhibitor and a 5-lipoxygenase inhibitor.